A long-lived charge-separated state of spiro compact electron donor–acceptor dyads based on rhodamine and naphthalenediimide chromophores

A long-lived charge-separated state of spiro compact electron donor–acceptor dyads based on rhodamine and naphthalenediimide chromophores Full article

Journal

Chemical Science
ISSN: 2041-6520

Output data

Year: 2022, Volume: 13, Number: 45, Pages: 13426-13441 Pages count : 16 DOI: 10.1039/d2sc04258d

Authors

Xiao Xiao ¹ , Kurganskii Ivan ^2,6 , Maity Partha ³ , Zhao Jianzhang ^4,1 , Jiang Xiao ⁵ , Mohammed Omar F. ³ , Fedin Matvey ^2,6

Affiliations

1	State Key Laboratory of Fine Chemicals, Frontiers Science Center for Smart Materials, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, P. R. China
2	International Tomography Center, SB RAS Institutskaya Str., 3A
3	Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
4	State Key Laboratory of Chemistry and Utilization of Carbon Based Energy Resources, College of Chemistry, Xinjiang University, Urumqi 830017, P. R. China
5	Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, P. R. China
6	Novosibirsk State University, Pirogova str. 2, Novosibirsk 630090, Russia

Spiro rhodamine (Rho)-naphthalenediimide (NDI) electron donor–acceptor orthogonal dyads were prepared to generate a long-lived charge separation (CS) state based on the electron spin control approach, i.e. to form the 3CS state, not the 1CS state, to prolong the CS state lifetime by the electron spin forbidden feature of the charge recombination process of 3CS → S0. The electron donor Rho (lactam form) is attached via three σ bonds, including two C–C and one N–N bonds (Rho-NDI), or an intervening phenylene, to the electron acceptor NDI (Rho-Ph-NDI and Rho-PhMe-NDI). Transient absorption (TA) spectra show that fast intersystem crossing (ISC) (<120 fs) occurred to generate an upper triplet state localized on the NDI moiety (3NDI*), and then to form the CS state. For Rho-NDI in both non-polar and polar solvents, a long-lived 3CS state (lifetime τ = 0.13 μs) and charge separation quantum yield (ΦCS) up to 25% were observed, whereas for Rho-Ph-NDI (τT = 1.1 μs) and Rho-PhMe-NDI (τT = 2.0 μs), a low-lying 3NDI* state was formed by charge recombination (CR) in n-hexane (HEX). In toluene (TOL), however, CS states were observed for Rho-Ph-NDI (0.37 μs) and Rho-PhMe-NDI (0.63 μs). With electron paramagnetic resonance (EPR) spectra, weak electronic coupling between the Rho and NDI moieties for Rho-NDI was proved. Time-resolved EPR (TREPR) spectra detected two transient species including NDI-localized triplets (formed via SOC-ISC) and a 3CS state. The CS state of Rho-NDI features the largest dipolar interaction (|D| = 184 MHz) compared to Rho-Ph-NDI (|D| = 39 MHz) and Rho-PhMe-NDI (|D| = 41 MHz) due to the smallest distance between Rho and NDI moieties. For Rho-NDI, the time-dependent e,a → a,e phase change of the CS state TREPR spectrum indicates that the long-lived CS state is based on the electron spin control effect.

Xiao X. , Kurganskii I. , Maity P. , Zhao J. , Jiang X. , Mohammed O.F. , Fedin M.
A long-lived charge-separated state of spiro compact electron donor–acceptor dyads based on rhodamine and naphthalenediimide chromophores
Chemical Science. 2022. V.13. N45. P.13426-13441. DOI: 10.1039/d2sc04258d WOS Scopus OpenAlex

Submitted:	Jul 30, 2022
Accepted:	Oct 25, 2022
Published online:	Oct 26, 2022
Published print:	Dec 7, 2022

Web of science:	WOS:000880796400001
Scopus:	2-s2.0-85142323671
OpenAlex:	W4311284439

DB	Citing
Scopus	22
Web of science	24